如何在安装了goclipse的eclipse中运行GO项目

If GOROOT refers to where go is installed (C:\Go), then you need to make sure that:

• GOPATH differs from GOROOT (it is important, because GOROOT/[src|pkg|bin] are folders for the Go language itself, not for your own sources)
• GOPPATH points to a folder under which all your different Go project will reside (for instance C:\Users\yourName\Go: that defines a workspace)
• your eclipse project is created in GOPATH\src\myproject

See "How to Write Go Code" to make sure that your installation and project sources respect the expected organization.

The OP Tiina reports in the comments:

Now it works, but I noticed two things odd.

• First what I did: I move helloTest folder into C:\Users\Tiina\go_workspace\src, so now it is at C:\Users\Tiina\go_workspace\src\helloTest.
• Then I create project from existing code. Nothing else changed. Now I have two GOPATH in explorer, one is C:\Users\Tiina\go_workspace\src, the other one is C:\Users\Tiina\go_workspace\helloTest\src.
  The latter one did no exist at the beginning

I suspect what goclipse does is define one GOPATH per project (or complete the existing GOPATH).
If you create or import a project, it will define/complete GOPATH in <that project/src>
If you hello.go is within that <that project/src/> folder, then it should build and work as expected.

The user guide "project structure" of goclipse mentions:

项目位置不属于任何GOPATH条目。
在这种情况下，项目位置将隐式添加为一个条目的GOPATH，和去工作空间结构的bin，pkg和src目录将在项目中使用。

请注意，项目的隐式GOPATH条目仅适用于该项目中的源模块。其他Goclipse项目将看不到它（除非该条目已显式添加到global中GOPATH）。

在该src文件夹中，您可以创建Go源文件，这些源文件将被编译成一个库包（放入pkg）或可执行文件（放入bin）。